Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 edition. Excerpt: ... PART I THE METALS Reactions of the Metals of Group I The metals, silver, mercury (-ous), and lead, comprising this group, are distinguished from all others by the insolubility of their chlorides in water and in dilute acids. With the exception of the nitrates and acetates, which are colorless, nearly all the salts of the metals of this group are insoluble in water. Silver 1. Hydrochloric acid or a soluble chloride, when added to solutions of silver salts, gives a white, curdy precipitate of silver chloride (AgCl) which darkens on exposure to light. The precipitate is insoluble in water, the solubility being approximately 1 part in 700,000 parts of water; it is insoluble in dilute acids and in dilute aqua regia, but is somewhat soluble in concentrated acids. Ammonium hydroxide readily dissolves it, with the formation of silver ammonia chloride [Ag DEGREESH3 DEGREESCl]: -- AgCH-2NH8 = Ag(NH3)2Cl, from which AgCl reprecipitates onsacidification with nitric acid: -- Ag(NH3)2Cl + 2 HNO3 = VgCl + 2 NH4N03. Silver chloride also dissolves in somtions of potassium cyanide and sodium thiosulphate; DEGREES when cautiously heated, it fuses without decomposition. 2. Hydrogen Sulphide and soluble sulphides precipitate black Ag2S, insoluble in cold dilute acids, alkali hydroxides, and alkali sulphides; it is soluble in hot dilute HN03, with the formation of AgN03 and separation of sulphur. The reaction can be considered as taking place in two steps, the first consisting of the solution of the sulphide with the liberation of H2S and the second of the oxidation of the H2S by the excess of HN03 present with the formation of water, nitric oxide, and the separation of sulphur: -- (1) Ag2S + 2 HN08 = 2 AgN03+tH2S; (2) 2 HN03 + 3 H2S = 4 H20+f2 NO + 3 S. Multi